When traveling outside of the Earth's atmosphere, the magnetic fields and radiation levels increase. Radiation is a general term for energy which radiates out from a source and which can be a particulate or part of the electromagnetic spectrum. Radiation spectrometers are devices that are utilized to determine what kind of energy is present. When, for example, a large vehicle, such as an aircraft, spacecraft, or satellite travels through, for example, a variety of primary high-energy cosmic rays, i.e. radiation originating from outside the Earth's atmosphere, the vehicle may absorb the rays of energy and convert them into neutrons that generate nuclear energy inside of the aircraft. Typically, the thick structure of the vehicle multiplies the primary particles so that there are more neutrons trapped inside the vehicle than the original number of rays from the electromagnetic fields that created them.
Conventional radiation spectrometers or detectors may be characterized by several disadvantages. Some of the disadvantages associated with current radiation spectrometers are related to the fact that the weight, size, and power requirements of currently existing spectrometers make their use costly and problematic for many applications today. Currently, two independent instruments may be required to respond to high and low linear energy transfer (LET) emissions. Many applications today, whether space craft or ground based applications, may benefit from a radiation spectrometer device that has dual capability as it relates to high and low energy detection.
It has been common to design military and commercial aircraft with fly-by-wire control systems. In fly-by-wire systems, the aircraft is controlled, at least in part, by electrical signals generated from sensors in the aircraft. The sensors are often utilized to measure aerodynamic quantities that may affect the performance of the aircraft's controls. Sensors may also be utilized to measure a pilot's control actions. These fly-by-wire control systems may be affected by the radiation levels that exist in high altitudes. Thus, radiation spectrometers may be utilized to sense the type and quantity of the nuclear energy present.
A radiation spectrometer may also be utilized to alert an individual of the level of nuclear energy present. Because the spectrum of nuclear energy is vast, devices are typically designed to detect a portion of the spectrum. The spectrum can be divided into low linear energy transfer (LET) radiation and high LET radiation or into strongly penetrating radiation and weakly penetrating radiation (as an indication of its ability to penetrate shielding or the human body). Typically, a spacecraft may include a high LET spectrometer and a low LET spectrometer. Low LET may be defined as the energy transfer characteristic of light charged particles. Low LET may be characterized as radiation with low linear energy transfer, normally assumed to comprise photons (including X rays and gamma radiation), electrons, positrons and muons. Low LET may also be characterized according to the distance between ionizing events, which is large on the scale of a cellular nucleus. High LET refers to an energy transfer characteristic of heavy charged particles. High LET may be defined as radiation with high linear energy transfer, normally assumed to comprise protons, neutrons and alpha particles (or other particles of similar or greater mass).
When a separate high LET spectrometer and low LET spectrometer are utilized, an individual may experience difficulty transporting even a single spectrometer between different environments. Accordingly, it may be desirable to develop a spectrometer capable of detecting high LET radiation and low LET radiation. It may also be desirable to combine both the high and low radiation detection functions, and thus, reduce redundancy in component parts. Further, it is desirous to develop small and lightweight devices that are inexpensive to manufacture, and accordingly, reduce the cost to fly an aircraft. Moreover, it is desirous to develop a device that conserves power and thus, is less burdensome on flight resources.
A single LET spectrometer may weigh about 214 grams and be approximately 4.5 inches×4.5 inches×0.5 inches in size. It is well known that high LET spectrometers and low LET spectrometers have components in common. Accordingly, having a high LET spectrometer and a low LET spectrometer on board an aircraft or spacecraft results in redundancy, as each of the high and low radiation spectrometers have parts in common. Each spectrometer may also have its own power requirements, thus placing an addition burden on the aircraft or spacecraft.
Radiation spectrometers may also have applications on the ground. For example, radiation spectrometers may have security applications. These spectrometers may be used to detect radiation in shipping containers, at airport security locations or any ground based security station where radiation detection may be desired. Thus, any security applications where high and/or low radiation detection is desirable may have a need for a radiation spectrometer that can provide both levels of detection. Typically, both a high and low LET radiation spectrometer would be utilized. It may also be desirous to have a single portable spectrometer capable of detecting both high and low LET radiation for the ground based applications thereby reducing the number of test instruments required.
For reasons stated herein, there may be a need in the art to provide a small, lightweight radiation spectrometer device that detects both high and low LET radiation, reduces the cost of manufacturing and is pocket portable.